Insulator



2 Sheets-Sheet l D. H. OSBORNE INSULATOR Filed March 17 1927 May 13, 1930.

May 13, 1930. 0. H. OSBORNE 1,758,462

INSULATOR I Filed March 17, 1927 2 Sheets-Sheet 2 HuM/0/F/ER Patented May 13, 1930 UNITED STATES PATENT OFFICE DAVID OSBORNE, 0F JEFFERSONVILLE, PENNSYLVANIA, ASSIGNOR, BY MESN'E ASSIGNMENTS, '10 ELECTRIC SERVICE SUPPLIES COMPANY, OF PHILADELPHIA, FENNS'EELVANIA, A CORPORATION OF PENNSYLVANIA INSULATUT,

Application file l. March 1?, 1927. Serial No. 17653653.

This invention relates to insulators and with regard to certain more specific features,

to insulators used in connection with supports for electric lines.

Among the several objects of the invention may be noted the provision of an insulator comprising two or more parts, held in a predetermined relationship by a mass of an improved class of cement, having applied thereto an improved method or setting, whereby a commercial degree of strength is rapidly attained after manufacture; the provision of an insulator of the class described which, in view of the method employed, can be used soon after manufacturing, requiring no substantial curing period; the provision of an insulator of the class described wherein the mass of cement is used as a key, after hardening thereof has taken place, rather than as a surface bonding material; and the provision of an improved method of manufacturing insulators requiring a minimum amount of time and minimum cost but providing a better product. Other objects will be in part obvious and in part pointed out here inafter.

The invention accordingly comprises the elements and combination of elements, steps and sequence of steps, features of construction, andarrangements of parts which will be exemplified in the structure hereinafter described, and the scope of the application of which will be indicated in the following claims.

ltn the accompanying drawings, in which are illustrated several of various possible embodiments oi" th invention,

Fig. 1 is a side view, partly in section, of an insulator embodying this invention;

Fig. 2 is an enlarged sectional View of a portion of the insulator shown in Fig. 1;

Fig. 3 is a view similar to Fig. lshowing a modified form;

Fig. 4 is a view similar to Fig 2 showing a I interior of the recess 1n the top, are coated part of the insulator illustrated in Fig. 3;

Fig. 5 is a diagrammatic view illustrating the improved method of manufacturing;

- Fig. 6 is a fragmentary diagrammatic View illustrating a modified form of said method;

and

Fig. 7 is a diagrammatic view illustrating another modified form or" said method.

Corresponding reference characters indicate corresponding parts throughout the several views otthe drawings.

Insulators of the type to which his invention relates are composed of two or more parts which are connected together, usually by the use of Portland cement.

Amon the disadvantages attendant upon the use or Portland cement is the factthat it takes a relatively long time to attain a commercial degree of strength. In the present invention, method of manufacture and combination of materials is used which reduces this time required. An improved cement is used which provides a greater final commercial strength, and improved dielectric qualities.

This invention also provides an insulator so constructed that its parts will be eliectively secured together and at the same time so constructed as to substantially eliminate the concentration of the strains arising from operating conditions and changes in temperature.

Referring now more particularly to the drawings, which clearly illustrate the present improvements, there is illustrated at numeral 1 (Figs. 1 and 2) the center shell of an insu lat-or 2, provided with a recess 3 for the reception of a supporting pin, while the numeral 5 indicates a top or cap provided with a central recess within which the upper end of the shell 1 is adapted to extend, that is, when the top and center shell are assembled.

The upper end portion of the center shell 1, which is adapted to enter the recess 1n the top 5, is provided in its outer surface with one or more annular spaced grooves 7 of substantial-depth, The wall of the aperture in the top 5 is also provided with one or more grooves 9.

. Before assembly of the top and center shell, the upper part of the center shell and the with a compressible material 11 such as paraffine or sarco, the coating being of substantial thickness, but insulficient to fill the grooves 7 and 9.

The parts, after the coating with compressible material 11, are assembled and secured together by means of a layer of improved cement 13, which lies between the members and extends into and fills the grooves 7 and 9. This cement will be described more in detail hereinafter.

' It will now be noted that between the cement 13 and the adjacent surfaces of the center shell and the top 5 respectively, there is a layer of compressible material of substantial thickness, which prevents the cement from bonding to the porcelain surfaces and acts to compensate for any difference in the rate of expansion or contraction of the cement and of the porcelain, with changes in temperature, thus avoiding the setting up of strains on the porcelain. It will be also noted that the layers of compressible material substantially prevent concentration of strains between the center shell and top under conditions of service loading. Finally, it will be noted that the center shell and top are effectively secured together by the fact that the cement is keyed into grooves 7 and 9 in the shell and top.v

It is to be understood that this constructional portion of the invention is applicable in other forms, including added improvements. Another form is illustrated in Figs. 3 and 4.

In said Figs. 3 and 4, numeral 15 illustrates an insulating member comprising a skirt, hell or disc shape 17 having suitable convolutions and a cup shaped head section 19. A blind recess 21 extends upwardly into the head 19 from the underside thereof.

The insulator 15 is composed of porcelain or other suitable insulator material. The

inside and outside surfaces of the head p01 tion 19 are prepared so that the improved cement will not bond to said surfaces directly. The preparation of the surfaces is in the nature of a smoothing operation and one means of accomplishing it is to glaze the insulator. A hardware cap 23, composed preferably of metal, is adapted to slip over and loosely cooperate with said head 19 of the insulator. This cap 23 is of such dimensions that it has a spaced relationship with. respect to said head 19. Its lower end is formed as a bead 25, from the outer edge of which bead 25 there extends inwardly and downwardly a conical portion 27. The innermost lip 29 of the conical portion 27 is adapted to clear the outermost girth 31 of the head 19, whereby the members 19 and 23 may be loosely telescoped with one another. The outer surface of the porcelain insulator is formed with a relatively long taper 33 which extends downwardly and inwardly from the outermost girth section 31 to a fillet 35 which joins the head 19 with the skirt 17.

The upper portions 37 of the cap 23, above the head 25 are all spaced with respect to the head 19 but have a substantially parallel or similar relationship with respect thereto.

The said blind recess or socket 21 comprises a cylindrical portion 39 and an outwardly or an upwardly elongated flaring conical section 41. to loosely receive in spaced relationship thereto, a suspension member 43 having an upward tapered portion 45 of such diameter so as to slidably tit and clear said cylindrical portion 39. Suitable grooves or the like 44 may be formed in the cylindrical portion of.

the suspension member 43.

The loading surfaces of the engaging members described are coated with said yielding material used in the previously described form and numbered 47 in Figs. 3 and 4. After the surfaces in question have been coated, they areset into the relative positions illustrated in the drawings and at the same time layers of the improved cement (to load-transmitting surfaces are angularly arranged in an inverse manner, whereby the masses of cement therebetween function as keys to prevent separation of the surfaces. The angularity is attained by means of the conical portions described.

The improved form of cement to be used comprises what. is generally known as an aluminat-e cement, often called lumnite, which comprises a mixture of calcium oxide, aluminum oxide and iron oxide together with miscellaneous materials, mixed in suitable proportions to form a hydraulic cement, adapted to be mixed with water and (if desired) with an aggregate, such as sand or other divided material. The advantage of this cement is that the above-named ingredients when mixed with water actually have a chemical action, as well as the ordinary growth of crystals (the latter due to the water of crystallization).

The chemical action generates a certain amount of heat as the cement sets. The improved manufacturing process herein described is adapted (1) to supply to the ce ment the water that it requires for effective setting, and (2) to carry away this heat as the heat is generated. The cement thus attains a high degree of strengthand does this comparatively rapidly The result is not a The' described recess 21 is adapted deleterious quick setting but a growth of strength within a shorter time. N o extraneous heat is used.

The following approximate formulae are given in order to show the distinct difference between Portland cement and an aluminate cement:

Portland cement Alum-incite cement Si 2.0% A1 0 40% A1203 Fe203 Cat) 63.0% Miscellaneous 5.()%

lVlgU 3.0%

lmpurities 1.0%

As will be seen from the above, an aluminate cement is characterized by a high percentage of aluminum oxide. is hereinbefore indicated, the aluminate cement is slow setting and quick hardening Setting and hardening of cements are terms which should be distinguished, because setting refers to the loss of the adaptability to be molded and hardening is a subsequent phenomenon which represents increase in strength.

Ordinarily, the heating action which takes place during the hardening of an aluminate cement drives off surface water, thereby reducing the water of crystallization at said surface and causing crumbling. This invention is adapted, to provide water of crystallization as the heating proceeds.

Furthermore, this invention reduces the heating effect, whereby less original water is caused to be lost and a faster hardening rate attained. It has been found that a cooling process results in a faster rate of hardening with a higher final strength.

Another advantage of aluminate cements over Portland cement is that they have much higher insulating properties.

The improved manufacturing process includes means for providing water of crystallization for the cement, after it is positioned in the insulators, and at the same time providing cooling means.

One form of the improved manufacturing process is illustrated in Figure 5 in which a chamber 49 is employed, said chamber having a suitable charging door 51 and a rack 53 for supporting a quantity of insulators of the class described. An inlet 55 is associated with said chamber 49 and an outlet57, said inlet 55 communicating with a humidifying system 57, By this means humidified air is blown in at the inlet 55 and passes through the chamber 49 and out of the outlet 57. By this means the required amount of moisture for hydraulic action of the cement is introduced into the chamber. An ambient abnormally humidified atmosphere is maintainedabout the insulators. I

The chamber and its contents are cooled by providing a jacket 59 therearound, communicating with an inlet 61 and an outlet 68, the former supplied with a fluid which has been artificially or otherwise cooled. The fluid may comprise air, brine or other suitable substance.

The cooled substance circulates about the chamber 19 and leaves at the outlet 63. By this cooling means heat may be carried off. The cooling means will usually be artificial during hot weather. In any case cooling process is abnormal, that is, faster than would ordinarily obtain were the insulators 1nain taincd at the room temperature maintained where they are dried.

The heater circulation and/or cooling jacket may be omitted if desired, and the water spray delivered to a chamber in which the insulators are located,-with a drain for removing water that collects on the floor of the chamber.

The operation is as follows:

The component parts of the insulators are assembled with the plastic aluminate cement therebetween and introduced into the chamber 49 While the cement is in its wet state. The chamber 49 is closed and as the ordinary setting of the cement takes place, humidified air is forced into and through the. chamber while it is cooled from the outside. Thus moisture for water or crystallization is provided and as the heat generates, due to setting of the cement, said heat is carried away by means of the jacket 59. It is to be understood that auxiliary cooling coils may be placed directly between the insulators within the chamber, if desired.

In Fig. 6 is shown a slight modification in which a cold air connection (35 is made directly to the inside of the chamber as. The same result as above described is accomplished, except that local direct cooling is had instead of indirect cooling. The cold air exhausts from the opening 57 with the humidified air.

Fig. 7 illustrates one other form by means of which moistening ,and cooling may be carried on. In this form a container 67 is provided, also having a rack 69 therein for supporting a plurality of the insulators. A valved cold water connection 71 is provided for the container 67 and a valved overflow 7 3, as Well as a valved drain 75.

The operation of the Fig. 7 form comprises loading the rack 69 with assembled insulators (their cement in a wet state) and then slowly circulating cold water through the container 67. The valves 71, 73 are opened and the valve 75 closed. The position of the overflow is such as to maintain the liquid level 75 in the container at an elevation adapted to submerge the insulators.

Ifdesired, the water, instead of being circulated, may be charged into the container 67 up to a predetermined level and the supplythen out off. This charge of water Will absorb heat from the setting cement and at achieved and other advantageous results at- "-tained As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown intheaccompanying drawings shall be interpreted as illustrative and not in a limiting sense.

The disclosed method of manufacturing the insulators is not claimed herein as the same forms the subject matter of a divisional application, Serial Number 327,312, filed Dec. 20, 1928.

I claim:

1. The insulator comprising a plurality of members held together by a cementitious mass of aluminate cement.

2. The insulator comprising at least one insulating component and a cementitious mass of aluminate cement associated there- With.

3. An insulator assembly comprising an insulating member having a head, a cap adapted to slidably cooperate with the head, inverse conical surfaces on the head and cap in spaced relationship, a cementitious mass of aluminate cement between the head and cap separated from the surfaces thereof by a resilient coating.

4. An insulator comprising a plurality of insulating members assembled together, a layer of relatively hard material positioned between adjacent surfaces of said members and adapted to secure said members together and a layer of relatively soft material positioned between said relatively hard material and the surfaces of said members adapted to prevent bonding of said hard material to said members and adapted to permit expansion of said hard material independently of said members, said hard material comprising an aluminate cement.

5. An insulator comprising an insulating member having a head, a cap adapted to slidably cooperate with the head, inverse conical surfaces on the head and cap in spaced relationship, acementitious mass between the head and cap separated from the surfaces thereof by a resilient coating, said cementitious mass comprising a mixture containing a percentage of bauxite equal to that of any other ingredient therein.

6. An insulator comprising a plurality of insulating members assembled together, a layer of relatively hard material ositioned etween adjacent surfaces of sai members and adapted to secure said members together and a layer of relatively soft material positioned between said relatively hard material and the surfaces of said members adapted to prevent bonding of said hard material to said members and adapted to permit expansion of said hard material independently of said members, said hard material comprising a mixture containing a high percentage of aluminum. V

7 The insulator comprising members held in a predetermined relationship by a layer of material, said material comprising aluminate cement.

In testimony whereof, I have signed my name to this specification this 16th day of March, 1927 DAVID HENRY OSBORNE. 

